Catalyst is a chemical substance that change the rate of chemical reaction.
Characteristics of catalyst:
- Catalyst remains chemically unchanged during reaction. Its chemical composition still the same before and after reaction.
- Catalyst only change the rate of reaction.
- Catalyst does not change the quantity of the product formed.
- Catalyst is specific in its action.
- Only a small amount of catalyst is needed to achieve a big increase in rate of reaction.
- When a positive catalyst is used in a chemical reaction, it enables the reaction to occur through an alternative path which requires lower activation energy.
- As a result, more colliding particles are able to overcome the lower activation energy.
- This causes the frequency of effective collision to increase.
- Hence, the rate of reaction increases.
Decomposition of hydrogen peroxide by catalyst of manganese (IV) oxide